Field of the Invention
The invention relates to a flexible pipeline to transport a frozen medium which has an outer transversely to its longitudinal direction undulated limiting tube, arranged inside are its at least one transversely longitudinal to its direction undulated metal pipe to guide the frozen medium, as well as a metal composed cooling pipe to guide a second frozen medium, and by which it is evacuated in the available cavity in the limiting tube.
Such a pipeline would, for example, be used for supplying super conductive magnetic systems or cryogenic pumps or larger refrigeration units requiring a cooling medium. They should be flexible and possibly also have a longer length. The pipes used should preferably be composed of high grade steel. They are transversely to their longitudinal direction undulated and as a result not only bendable, but also stable against radial loads. The transversely to their longitudinal direction extending undulations can be constructed helically shaped or ring shaped.
Description of Related Art
In the known pipeline according to EP 2 253 878 B1 there is a second pipe system arranged, between the guiding pipe and the limiting pipe, to guide a thermal screen for the frozen medium conducted through the guiding pipe serving other frozen mediums. The second pipe system is composed of an inner transversely to its longitudinal direction undulated pipe of metal and one with distance and coaxially to the same arranged outside, also transversely to its longitudinal direction undulated pipe of metal. The inner pipe of the second pipe system is arranged spatially close to the guiding pipe of the pipeline and between the guiding pipe of the pipeline and the inner pipe of the second pipe system is a guiding pipe in its relative position to the inner pipe is arranged an immovable holding spacer composed of insulation material. This known pipeline has proven valuable in practice. However, it definitely has a relatively large outer diameter because of the four concentric pipes arranged at a distance from each other.
From the previously mentioned U.S. Pat. No. 3,565,118 A, a pipeline is described which has a guiding pipe composed of metal to guide a frozen medium, where, for example, it deals with a liquid helium, which is fed into the guiding pipe with a temperature of, for example, 4.5 K. Wrapped around the guiding pipe is a rectangular cross section helically shaped band serving as a spacer, that can also be composed of metal. Wound around that band together in the same reverse impact direction is a helically shaped cooling pipe, which guides an outer frozen medium, which deals with a liquid nitrogen with a temperature of, for example, 80 K. Around the unit of guiding pipe and cooling pipe is a placed a metal layer, around which is wound a second helically formed spacer constructed as a band. Over the spacer lies an insulation composed of a plurality of layers, which is surrounded by a transversely to its longitudinal direction undulated outer limiting pipe.